The present invention relates to a composition for permanent shaping of hair which contains 2-hydroxy-3-mercaptopropionic acid as an effective keratin-reducing ingredient and a process for permanent shaping of hair using this composition.
The well known classic method for performing the permanent shaping of hair consists of opening the disulfide bonds of the hair keratin with the aid of an agent (hair shaping composition) which contains a reducing agent, putting the hair in the desired form or shape and subsequently reforming the disulfide bridges again using an agent containing an oxidizing agent (fixing composition).
Sulfite, thioglycolic acid, thiolactic acid, 3-mercaptopropionic acid, mercaptocarboxylic acid ester, Cysteine and its derivatives or Cysteamine and its derivatives are used as reducing agents in the method.
It is known that mercaptocarbonic acid ester, for example thioglycolic acid glycerin ester, are not satisfactory in regard to their skin compatibility and their sensitizing properties, while the thioglycolic acid has a high toxicity in comparison to Cysteine.